Biology subjects

Turtoi, A.

Publications and source records attributed to Turtoi, A..

11 recordsLinked to original sources

bioRxiv2025

Multi-Omics Reprogramming Drives a Counterintuitive Reversal of Disease Susceptibility During Ageing

Ageing is a progressive and irreversible biological process characterized by the deterioration of physiological functions and increased vulnerability to mortality. Although extensively studied in vertebrates, ageing in long-lived invertebrates remains comparatively unexplored. While ageing typically leads to greater susceptibility to infectious diseases, a striking and unexpected reversal was identified in oysters: older oysters exhibit markedly increased tolerance to the Pacific Oyster Mortality Syndrome (POMS), a panzootic disease primarily driven by the OsHV-1 herpesvirus and responsible for severe losses in global aquaculture. To investigate this counterintuitive pattern, we challenged oysters aged 4, 16, and 28 months from four biparental families and conducted an integrative multi-omics analysis, including epigenomics, transcriptomics, and metabolomics on the two families showing the strongest age-related increase in survival. Our results reveal that ageing in Magallana gigas is characterized by coordinated epigenetic, transcriptional, and metabolic reprogramming that reduces host permissiveness to POMS. We show that the epigenetic remodeling of key immune regulators (e.g., Toll-like receptors, MyD88) aligns with transcriptional rewiring of NF-{kappa}B and ubiquitin pathways, producing a finely tuned innate immune state marked by enhanced antiviral activity but reduced antibacterial responsiveness. We also identify age-related repression of mTOR signaling, likely promoting autophagy and improving viral control. These regulatory changes are tightly linked to metabolic adjustments, including reduced TCA cycle flux, remodeled nitrogen metabolism, and altered glutathione dynamics, which collectively support a stress-tolerant, energy-conserving phenotype. Together, our findings reveal a fundamental evolutionary trade-off: juveniles prioritize growth at the cost of viral susceptibility, whereas adults invest in cellular maintenance and antiviral preparedness.

genomics↗

bioRxiv2025

FMO4 drives lung adenocarcinoma by stabilizing the MAT2A/MAT2B complex and hindering ferroptosis

Lung cancer is the leading cause of death by cancer in the world and finding new targets is a major medical need to tackle this disease. Here, upon proteomic analysis to identify common players in oncogenic EGFR- and KRAS-driven lung adenocarcinoma mouse models, we uncovered a largely unknown protein in cancer, flavin-containing monooxygenase 4 (FMO4), whose expression was increased in lung tumors compared with adjacent lung tissue. FMO4 expression was strongly increased also in lung cancer samples from patients compared with healthy lung, and its expression level was inversely correlated with overall survival. Remarkably, in vivo deletion of FMO4 greatly decreased tumor burden and increased survival in oncogenic KRAS-driven lung adenocarcinoma mice unveiling its crucial role in tumor biology. Mechanistically, we found that FMO4 loss of function promotes ferroptosis and cooperates with ferroptosis inducers in vitro and in vivo. Moreover, FMO4 facilitates the interaction between MAT2A and MAT2B, promoting the generation of cysteine from methionine, which in turn boosts the generation of glutathione, thus protecting lung adenocarcinoma against ferroptosis. In summary we identified a new target in lung adenocarcinoma with important implications in cancer biology.

cancer biology↗

bioRxiv2023

Tuft cell-derived acetylcholine is an effector of type 2 immunity and directly targets helminth parasites in the gut lumen

Upon parasitic helminth infection, activated intestinal tuft cells secrete IL-25, which initiates a type 2 immune response during which lamina propria ILC2s produce IL-13. This causes epithelial remodelling, including tuft cell hyperplasia with an unknown function. We describe a novel cholinergic effector function of tuft cells, which we show are the only epithelial cells expressing Choline Acetyltransferase (ChAT). During parasite infections, mice with epithelial-specific deletion of ChAT have increased worm burden and faecal egg counts although they are able to mount a comparable type 2 immune response. Mechanistically, IL-13-amplified tuft cells release acetylcholine (ACh) into the gut lumen. We demonstrate a direct effect of ACh on worms, reducing their viability and fecundity via helminth muscarinic ACh receptors, with effects promoted by inhibition of acetylcholinesterase, an helminth-secreted enzyme. Thus, tuft cells are sentinels in naive mice, and their amplification upon helminth infections serves an additional type 2 immune response effector function.

immunology↗

bioRxiv2023

Defects in AMPAR trafficking and microglia activation underlie socio-cognitive deficits associated to decreased expression of Phosphodiesterase 2A

Phosphodiesterase 2A (PDE2A) is an enzyme involved in the homeostasis of cAMP and cGMP and is the most highly expressed PDE in human brain regions critical for socio-cognitive behavior. In cortex and hippocampus, PDE2A expression level is upregulated in Fmr1-KO mice, a model of the Fragile X Syndrome (FXS), the most common form of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Indeed, PDE2A translation is negatively modulated by FMRP, whose functional absence causes FXS. While the pharmacological inhibition of PDE2A has been associated to its pro-cognitive role in normal animals and in models of ID and ASD, homozygous PDE2A mutations have been identified in patients affected by ID, ASD and epilepsy. To clarify this apparent paradox about the role of PDE2A in brain development, we characterized here Pde2a+/- mice (homozygote animals being not viable) at the behavioral, cellular, molecular and electrophysiological levels. Pde2a+/- females display a milder form of the disorder with reduced cognitive performance in adulthood, conversely males show severe socio-cognitive deficits throughout their life. In males, these phenotypes are associated with microglia activation, elevated glutathione levels and increased externalization of GluR1 in CA1, producing reduced mGluR-dependent LTD. Overall, our results reveal molecular targets of the PDE2A-dependent pathway underlying socio-cognitive performance. These results clarify the mechanism of action of pro-cognitive drugs based on PDE2A inactivation, which have been shown to be promising therapeutic approaches for Alzheimer Disease, schizophrenia, FXS as well as other forms of ASD.

animal behavior and cognition↗

bioRxiv2023

Cancer-associated Fibroblast Spatial Heterogeneity and EMILIN1 Expression in Cancer Stroma Modulate TGF-beta Activity and CD8+ T-Cell Infiltration in Breast Cancer

The tumor microenvironment (TME) and its multifaceted interactions with cancer cells are major targets for cancer treatment. Single-cell technologies have brought major insights into the TME, but the resulting complexity frequently precludes conclusions on function. Therefore, we combined single-cell RNA sequencing and spatial transcriptomic data to explore the relationship between different cancer-associated fibroblast (CAF) populations and immune cell exclusion in breast tumors. Our data show for the first time the degree of spatial organization of different CAF populations in breast cancer. We found that IL-iCAFs, Detox-iCAFs, and IFN{gamma}-iCAFs tended to cluster together, while Wound-myCAFs, TGF{beta}-myCAFs, and ECM-myCAFs formed another group that overlapped with elevated TGF-{beta} signaling. Differential gene expression analysis of areas with CD8+ T-cell infiltration/exclusion within the TGF-{beta} signaling-rich zones identified elastin microfibrillar interface protein 1 (EMILIN1) as a top modulated gene. EMILIN1, a TGF-{beta} inhibitor, was upregulated in IFN{gamma}-iCAFs directly modulating TGF{beta} immunosuppressive function. Histological analysis of 74 breast cancer samples confirmed that high EMILIN-1 expression in the tumor margins was related to high CD8+ T-cell infiltration, consistent with our spatial gene expression analysis. High EMILIN-1 expression was also associated with better prognosis of patients with breast cancer, underscoring its functional significance for the recruitment of cytotoxic T cells into the tumor area. In conclusion, our data show that correlating TGF-{beta} signaling to a CAF subpopulation is not enough because proteins with TGF-{beta}-modulating activity originating from other CAF subpopulations can alter its activity. Therefore, therapeutic targeting should remain focused on biological processes rather than on specific CAF subtypes.

cancer biology↗

bioRxiv2022

Inferring ligand-receptor cellular networks from bulk and spatial transcriptomic datasets with BulkSignalR

The study of cellular networks mediated by ligand-receptor interactions has attracted much attention recently owing to single-cell omics. However, rich collections of bulk data accompanied with clinical information exists and continue to be generated with no equivalent in single-cell so far. In parallel, spatial transcriptomic (ST) analyses represent a revolutionary tool in biology. A large number of ST projects rely on multicellular resolution, for instance the Visium platform, where several cells are analyzed at each location, thus producing localized bulk data. Here, we describe BulkSignalR, a R package to infer ligand-receptor networks from bulk data. BulkSignalR integrates ligand-receptor interactions with downstream pathways to estimate statistical significance. A range of visualization methods complement the statistics, including functions dedicated to spatial data. We demonstrate BulkSignalR relevance using different bulk datasets, including new Visium liver metastasis ST data, with experimental validation of selected interactions. A comparison with other ST packages shows the significantly higher quality of BulkSignalR inferences. BulkSignalR can be applied to any species thanks to its built-in generic ortholog mapping functionality.

bioinformatics↗

bioRxiv2021

SPARC in cancer-associated fibroblasts is an independent poor prognostic factor in non-metastatic triple-negative breast cancer and exhibits pro-tumor activity

PurposeTriple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and lacks specific targeted therapeutics. The current mechanistic evidence from cell-based studies suggests that the matricellular protein SPARC has a tumor-promoting role in TNBC; however, data on the clinical relevance of SPARC expression/secretion by tumor and stromal cells in TNBC are limited. Experimental DesignThis study analyzed the prognostic value of tumor and stromal cell SPARC expression in a large series of 148 patients with non-metastatic TNBC and long follow-up (median: 5.4 years). Fibrosis, tumor-associated macrophage (TAM) infiltration, tumor-infiltrating lymphocyte (TIL) density, PD-L1 and PD-1 expression were assessed. Tumor and stromal cell SPARC expression was studied by immunofluorescence, western blotting, and meta-analysis of published single-cell mRNA sequencing data. The biological role of fibroblast-secreted SPARC was analyzed using cell adhesion, wound healing, Transwell-based motility and invasion, and tumor spheroid assays. ResultsSPARC expression was detected in cancer cells (42.4%), cancer-associated fibroblasts (CAFs) (88.1%), TAMs (77.1%), endothelial cells (75.2%), and TILs (9.8%). Recurrence-free survival was significantly lower in patients with SPARC-expressing CAFs. SPARC expression in CAFs was an independent prognostic factor in multivariate analysis. Tumor and stromal cell SPARC expression was observed in TNBC cytosols, patient-derived xenografts, and cell lines. SPARC was expressed by different CAF subsets, including myofibroblasts and inflammatory CAFs. Fibroblast-secreted SPARC inhibited TNBC cell adhesion and stimulated their migration and invasion. ConclusionsSPARC expression in CAFs is an independent predictor of recurrence-free survival in TNBC. Patients with SPARC-expressing CAFs could be eligible for anti-SPARC-targeted therapy. Statement of translational relevanceHere, we identified a subgroup of patients with triple-negative breast cancer (TNBC) with worse prognosis and eligible for therapies that target extracellular matrix proteins in the tumor stroma. Specifically, we found that expression of the matricellular protein SPARC in cancer-associated fibroblasts (CAFs) is an independent prognostic marker of poor outcome in TNBC. Furthermore, we showed that in TNBC, SPARC is expressed by different CAF subpopulations, including myofibroblasts and inflammatory fibroblasts that are involved/associated with many tumor-related processes. We then found that SPARC secreted by fibroblasts has a pro-tumor-promoting role by inhibiting TNBC cell adhesion and stimulating their motility and invasiveness. Overall, our results support the need to consider SPARC expressed/secreted by CAFs as a novel therapeutic target in TNBC in the context of treatments to modulate the tumor stroma.

cancer biology↗

bioRxiv2021

Tumor-Antagonizing Fibroblasts Secrete Prolargin as Tumor Suppressor in Hepatocellular Carcinoma

Systemic treatment of hepatocellular carcinoma (HCC) targets the tumor microenvironment (TME) by combining immunotherapy with angiogenesis inhibitors. Cancer-associated fibroblasts (CAF) are important components of the TME, however their targeting in clinics remains challenging. To this end, the existence of tumor supressing CAF and their poor characterisation is a major conundrum. Starting from proteomics and single cell analysis, we outline CAF heterogeneity in HCC and describe a subtype of CAF that express a novel tumor-related protein prolargin. Upon secretion prolargin is deposited in the TME where its levels positively correlate with patient outcome (HR=0.37; p=0.01). In vivo, tumors with lower prolargin expression display faster progression (5-fold; p=0.01) and stronger angiogenesis. Mechanistically, aggressive HCC cells degrade prolargin using matrix metalloprotease 3 (MMP3). We show that prolargin binds and inhibits several growth factors, key to tumor progression. Inhibiting prolargin degradation combined with sorafenib, demonstrated superior tumor control compared to sorafenib treatment alone. In conclusion, prolargin-expressing CAF have tumor-antagonizing properties. Stabilizing prolargin tumoral levels should be considered for systemic therapy of HCC, involving CAF in existing TME targeting.

cancer biology↗

bioRxiv2020

Control of polyunsaturated fatty acids desaturation by Sting regulates inflammatory responses

Inflammatory disorders are major health issues in which immune function and metabolic homeostasis are concertedly altered. Yet, the molecular mechanisms coordinating innate and metabolic pathways in homeostatic conditions are poorly understood. Here, we unveil a negative regulatory feedback loop involving the Stimulator of interferon genes (Sting) and the Fatty acid desaturase 2 (Fads2). At steady state, Sting regulates FA metabolism by repressing the activity of the Fads2 enzyme responsible for the desaturation of polyunsaturated FAs (PUFAs). Importantly, Sting activation increased Fads2 activity, while antagonizing Fads2 enhanced Sting activation, promoting the establishment of an anti-viral state. Remarkably, the cross-regulation between Sting and Fads2 is mediated by the cyclic GMP-AMP (cGAMP) Sting agonist and PUFAs. Indeed, we found that PUFAs inhibit Sting activation, while Sting agonists bind Fads2. Thus, our study identifies Sting as a master regulator of FA metabolism, and PUFAs as modulators of Sting-dependent inflammation. The interplay between Fads2 and Sting determines the fine-tuning of inflammatory responses, but comes at the expense of metabolic alterations, which are critical to consider in human pathologies associated with aberrant Sting activation.

immunology↗

bioRxiv2019

Partial loss of colonic primary cilia promotes inflammation and carcinogenesis

Primary cilia (PC) are important signaling hubs in cells and their deregulation has been associated with various diseases including cancer. Here we explored the role of PC in colorectal cancer (CRC) and colitis. In the colon we found PC to be mostly present on different subtypes of fibroblasts. Colons of mice exposed to either chemically induced colitis-associated colon carcinogenesis (CAC) or dextran sodium sulfate (DSS)-induced colitis had decreased numbers of PC. We employed conditional knock-out strains for the PC essential genes, Kif3A and Ift88, to generate mice with reduced numbers of PC on colonic fibroblasts. These mice showed an increased susceptibility in the CAC model as well as in DSS-induced colitis. Colons from DSS-treated mice with PC-deficiency on fibroblasts displayed an elevated production of the pro-inflammatory cytokine IL-6 and colonic epithelial cells had diminished levels of HES-1, a key transcription factor of Notch signaling. Notably, an analysis of PC presence on biopsies of patients with ulcerative colitis as well as CRC patients revealed decreased numbers of PC on colonic fibroblasts in pathological versus surrounding normal tissue. Taken together, we provide evidence that a decrease in colonic PC numbers promotes colitis and CRC. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=177 HEIGHT=200 SRC="FIGDIR/small/871772v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@1f8eccdorg.highwire.dtl.DTLVardef@1829b3borg.highwire.dtl.DTLVardef@19d632aorg.highwire.dtl.DTLVardef@1d9833b_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2019

The molecular landscape and microenvironment of salivary duct carcinoma reveal new therapeutic opportunities

Salivary duct carcinoma (SDC) is a rare and aggressive salivary gland cancer subtype with poor prognosis. The mutational landscape of SDC has been described rather exhaustively; yet, with respect to functional genomics and tumor microenvironment, little is known. In this study, transcriptomics and proteomics were combined to obtain the first characterization of the pathways deregulated in SDC. The data revealed the importance of Notch, TGB-{beta}, and interferon-{gamma} signaling. After associating computational biology, immunohistochemistry, multiplexed immunofluorescence, and digital imaging the first steps towards charting the cellular network within the microenvironment was initiated. According to immune infiltrate, two well-defined groups of tumors were observed, novel SDC immune checkpoints were discovered, and the key role played by macrophages and potentially NK cells in immunosuppression was shown. Furthermore, a clear trend between recurrence-free survival and M2 macrophage abundance was apparent. Independently, a measure of desmoplastic stromal reaction as determined by -SMA abundance, was also shown. Altogether, these many findings open new perspectives for understanding and treating SDC. Before applying an immunotherapy, classical patient stratification according to immune infiltrate should be taken into account. Moreover, the microenvironment offers new potential targets including macrophages or NK cells, or even fibroblasts or hyaluronic acid. Related therapies that have been developed against, e.g., pancreatic tumors could inspire equivalent therapy for SDC.\n\nAdditional informationO_LIFinancial support: MA (1 grant, GIRCI SOOM API-K 2016-811-DRC-AC), JC (2 grants, Fondation ARC PJA 20141201975, Labex EpiGenMed ANR 10-LABX-0012), AT (2 grants, Gunma University GIAR Research Program for Omics-Based Medical Science, Labex MabImprove ANR 10-LABX-0053 starting grant), ET (1 grant, SIRIC Montpellier Cancer Grant INCa_Inserm_DGOS_12553).\nC_LIO_LINo conflict of interest\nC_LIO_LI5408 words, 1 table, and 4 figures\nC_LI\n\nStatement of translational relevanceBased on the presence or absence of an immune infiltrate, two groups of SDC were identified. These have the potential to provide a rationale for therapy and clinical trial enrolment. Two novel immune checkpoints that could be targeted were also identified; namely, CTLA-4/CD86 and TIM-3/galectin-9. Both showed the important contribution that macrophages and NK cells have in immunosuppression. Treatments that induce reprogramming or elimination of these cells could be considered. Moreover, the importance of the desmoplastic stroma was stressed. The stroma acts as a physical barrier against therapy suggesting that strategies developed against pancreatic tumors could inspire SDC treatments. For SDC devoid of immune infiltrate, components of the stroma including fibroblasts or hyaluronic acid could be targeted, e.g., in combination with drugs against immune checkpoints or mutated genes. Finally, evidence that Notch and TGF-{beta} signaling are prevalent in SDC was obtained. This translates into additional therapeutic options.

cancer biology↗